Common issue with NXT (not just in the LabVIEW environment)..kind of hit and miss to resolve. I'm sure you've tried many of these already, but here goes...
Here are some methods where we have had some success:
- PATIENCE - it can take up to 45 seconds for the NXT to complete the hand-shaking (pass code etc..) REPEAT the connection attempt if it fails on the first try. Sometimes that takes. Be sure the NXT battery is fully charged.
- Restarting the PC (including. reseating the bluetooth dongle). At times you might see a COM port number displayed by windows in the lower right corner of the screen during the connection. We find that the higher that number (30s and 40s), the more likely it won't connect. It's happier with low assignments (<15). (Perhaps some work at the operating system level, you could delete bluetooth devices, etc..) We sometimes have this COM port issue effect our joy-sticks in the RC Editor too - we have to clear out Device Manager entries to remedy that.
- Remove the NXT from the list. SCAN fresh.
- CONNECT from the NXT to the PC - as a last resort this can sometimes work. From the NXT go to the Bluetooth menu and attempt to connect to the PC. You will be asked to enter the Pass Code from the PC (1234).
- Clear out the Contact list of PC names on the NXT (under the bluetooth menu). Start fresh, be patient, all of the above...
- Turn off the SAMANTHA module. Unplugging the USB to the NXT might be enough. However, it is still generating a signal unless the power is disconnected. (Warning: we have noticed minor programming anomalies when running with/without the Samantha module connected.)
Perseverance reigns. If you come up with a sure fix, I'd love to hear it!
